Combustion engine



Dec. 6, 193s.

'7 Sheets-Sheet 1 d l wl.. i

Mq no 6, 1938. H, RlEsELER coMBUsTIoN' ENGINE '7 Sheets-Sheet 2 oasiFiled oct. 12, 19:55

H. RIESELER COMBUSTION ENGINE Dec. 6, 1938;.

- Filed Oct. 12, 1955 '7 Sheets-Sheet 5 ,icy ma Hw Dec. 6, 193s. H,MESELER- y "2,139,284

coMBUsTloN ENGINE` Filed Oct: 12, 159:55A 7 Sheets-Sheet 4 ATTORNEY Dec.6, 1938. H. mest-:LER 2;139,284

coMBusTroN ENGINE:l

' =r ATTORNEY i Dec. (i,V 1938. H.- RlEsELER 2,139,284

COMBUSTION ENGINE Filed oct. 12, 19:55` 7 sheets-sheet s ffy. z

" 6, 1938, H. RlEsELR CoMBUsTroN ENGINE 'Filed oct. 12-l 1935 7Sheets-Sheet 7 #oww/M Q7 maf* i Patented Dec. 6, 1938 UNITED STATESPATENT OFFICE COMBUSTION ENGINE Hermann Rieseler, Kiel, GermanyApplication October 12, 1935, Serial No. 44,662

3 Claims.

This invention relates to combustion engines.

One object `of the invention is vthe provision of a novel combustionengine construction and method of operation thereof, which provides for5 widev variation in engine torque with a. very economical fuelconsumption.

Another object of the invention is the provision of an engine in whichthere is an exceptionvally large temperature drop in the expansion ofthe hot products o f combustion in an expansion chamber, to which theproducts of combustion are supplied through a pressure regulating intakevalve `which is provided between the expansion chamber and a preliminarycombustion space in which the combustion originates.

lAnother object of the invention resides Iin an engine construction ofthe character mentioned 'in which the preliminary combustion space iscooled by combustion air furnished at high pres- 20 sure from an aircompressor which is independent of the work engine.

Another object of the invention is the provision of a combustion engineof the' character mentioned, having provision for regulating thepressure of the compressed air which is supplied to the preliminarycombustion space, enabling wide variations in torque of the workproducing parts of the apparatus, the air compressor being drivenindependently of the work producing parts ofthe apparatus preferably bya separate combustion engine.

Another object of the invention is the provision of an engine having awork or expansion cylinder in which hot products of combustion areexpanded and having a preliminary combustion space from which the hotproducts of combustion are supplied through a pressure regulating valveto the work cylinder, the compressed air flowing to the preliminarycombustion space .being passed along the walls of the gas conductingchannel ahead of the intake valve of the work cylinder and along thewalls of -the preliminary combustion chamber so as to coolthe walls andthus regulate the temperature of these walls to prevent them frombecoming excessively hot, the heat applied to the compressed air beingeffective in bring the air temperature substantially up to the ignitiontemperature of the fuel introduced into the preliminary combustion spaceso that this heat is not lost in the work process of the engine.

Another object of the invention is the provision in an engine of thecharacter mentioned, of a preliminiary combustion chamber provided aheadofthe work expansion chamber, so ar- Germany November 22, 1932 ranged asto give a very short flow path between the inlet valve and the expansioncylinder.

Another object of the invention is the provision, in a combustion engineof the character mentioned, of a valve governing the flow of hotcombustion gases from the preliminary combustion chamber to the work orexpansion chamber, the valve being so constructed as to automaticallythrottle the flow, providing increased throttling effect at increasedspeeds and thus automatically governing the torque vof the engine bygoverning the degree of filling of the expansion chamber.

Further objects and advantages of the invention will be apparent fromthe following descrip- 15 tion, the appended claims and the accompanyingdrawings, in which- Fig. l is a diagrammatic representation of an engineor power plant embodying the present invention;

Fig, 2 is a diagrammatic view of a slightly modified form ofconstruction providing for manual control of the compressed airreservoir pressure;

Fig. 3 is a diagrammatic view of another modification of the inventionin which a slightly different form of control is provided for theregulation of the pressure of the compressed air reservoir chamber;

Fig. 4 is a diagrammatic showing of another modification of the enginein which manual adjustments of different controlled elements arenffected through a servomotor which is operated by, air supplied fromthe compressed air reservoir;

Fig. 4a is a diagrammatic showing of an adjusting device according toFig. 4 at a larger scale. l l

Figs'. 4b, 4c, and 4d respectively are sectional views on themes 1lb-4b,4er-4c, and afi-4a, 40 of Fig. 4a;

Fig. 5 is a diagrammatic showing of the timing of the fuel injection andinlet valves of a cylinder of the engine represented in Fig. 6;

Fig. 6 is a diagrammatic showing of a portion of the elements of a powerplant embodying the present invention in which an individual fuelinjection chamber is provided for each work or expansion chamber of theengine;

Fig. 'l is a vertical section taken centrally through a work orexpansion cylinder and showing the inlet valve and preliminarycombustion chamber;

Fig. 8 is a section on the line 8-8 of Fig. 7; 55

Fig. 9 is a sectional view on the line I-l of Fig. 6;

Fig. 10 is a diagrammatic view of two pressure volume diagrams of theengine of the present invention as illustrated in the construction shownin Figs. 2 and 3 for example, and in which the intake pressures differsat an approximately constant filling period; and

Fig. 11 is a diagrammatic showing of pressure volume diagrams of theengine of the present invention, corresponding for example to theconstruction shown in Figs. 1 and 4, and in which there is anapproximately uniform pressure of combustion gases supplied to theexpansion chamber, and showing the results of throttllng of the flow tothe expansion chamber at different speeds of operation.

Fig. 12 is an enlarged showing of one of the fuel pumps.

Fig. 13 is a longitudinal section on shaft I2b of Fig. 3, takenvertically. l

Referring more particularly to the drawings by reference numerals, andfirst with more particular reference to the power plant construction ofFig.,1, the invention as herein disclosed provides for the automaticregulation' of the mean pressure of the gases supplied to the workcylinder in accordance with the speed of engine operation. The numeral Idesignates an engine such as a Diesel engine of any suitable characterwhich is mechanically connected in driving relation with the aircompressor 2, being coupled thereto in any desired manner. Asillustrated. engine l and air compressor 2 have a common crankshaft 2I0.The air compressor supplies compressed air to a reservoir chamber 'Ifrom which it flows, past the control valve l, to the preliminary orcombustion chamber 4 which is arranged ahead of the intake element orvalve 5 of the work engine incorporating the piston and cylinder 3, inwhich the hot combustion gases are expanded, with the production ofwork.

As will be apparent from the drawings, the work or expansion chamber 3and the preliminary or combustion chamber l is mechanically independentof any driving connection with the air compressor 2 and its drivingmotor I.

A pressure regulating device 8 is provided, as shown, for the automaticcontrol of the fuel supply device of the engine I and to control thefuel supplied to the combustion chamber l in accordance with thepressure of the air in the reservoir 1, the pressure regulator I thuskeeping a substantially uniform air pressure in the reservoir l. Theregulator 8 controls the fuel regulating part 9 for the fuel pump IIIwhich governs the amount of fuel supplied to the fuel injection nozzle|50 of the engine I. similar in constructionto the fuel pump I I and thetwo pumps, as shown, are controlled by a regulating rack 9 engaging gearteeth Ill, see Fig. 12, that are provided on the reciprocating pumppistons. Lateral movement of rack 3 is controlled by a lever- Iconnected to the regulator 8. The pump piston for the pump I I is givenreference numeral MI, this piston being operated by a fuel pump cam 2I2.The time duration of the supply of fuel oil to the pipe Iis determinedby the angular setting of lthe pump plunger. Such pump construction iswell known, and shown for example in U. B. Patent 1,967,101. Thepressure regulator is also mechanically connected to the air inlet valve2l. of the air compressor 2 so as to automatically control the amount ofair drawn into the air compressor The fuel pump Il is and thus governsthe pressure of the air flowing from the smaller cylinder of thecompound air compressor. If the pressure in reservoir 'I increases,angular lever 20I draws nearer to the shaft of inlet valve 20 andprevents a complete closing of the valve. In this form of construction,as will be noted, the fuel pumpv Il which supplies fuel to thepreliminary or combustion chamber I is driven from the same pump drivingshaft which is utilized for the operation of the fuel pump of the engineI. Thus, as illustrated, fuel pumps I0 and II are driven by cams 2II and2I2 on camshaft 2I3, which is gear driven from crankshaft 2I|| by meansof gears 2| 4 and 2I5.

As will be more fully described, the fuel supplied to the combustionchamber 4 is burned with the warm compressed air supplied from thereservoir chamber 1, and the hot products of combustion or the burninggases are supplied to the expansion or work cylinder 3 under the controlof a timed valve 5 which is driven in timed relation with the movementsof the Work piston 3 by means of a cam shaft I2 suitably geared orconnected to the power-output shaft 2I6 to which the piston 3 isconnected. As shown, power output shaft 2 I6 carries sprocket 2IIdriving sprocket 2|8 on shaft I2 by means of chain 2I9. The cam shaft I2also carries an outlet valve cam 30a for the control of the outlet orexhaust valve of the cylinder 3 which may be of any suitable andwell-known construction, as shown.

The cam shaft I2, which preferably operates at the same speed as thecrank shaft of the work cylinder, is shiftable endwise in order tochange the stroke of the intake valve 5 and also to provide for reversalof engine operation, endwise movement of the shaft I2 being accomplishedby means of a mechanical servomotor I3 of any suitable character. Thus,as illustrated, camshaft I2 carries collar 220, which is engaged by oneend of lever I8 pivoted at 222. 'I'he other end of lever I8 is driven byservomotor I3. The servomotor is represented in Fig. 4a and its methodof working described further below. The servomotor is controlled bymeans of centrifugal regulator Il which automatically positions a leverI6 in accordance with the speed of operation of the work cylinder. 'I'helever I6 is fulcrumed at a point I5 and the fulcrum point is movablealong the length of the lever I6 in order to provide for reversal of thedirection ofl engine operation. Shifting of the fulcrum I5 isaccomplished by a manually controlled lever I5', as shown. Movement ofthis lever I5 from the position illustrated, in' a clockwise direction,lowers the slidable fulcrum I5 to the other side of the point of pivotalconnection between lever I6 and governor Il. With the fulcrum I5 in theposition shown between the pivotal connection of governor Il" and the'vpivotal connection of servomotor I3 to lever I6, it is apparent thatmovement of governor I4 in one direction will produce movement of theconnection of servomotor I3 in the opposite direction, with resultantmovement of camshaft I2. When, however, fulcrum I5 is moved below thepoint of attachment of governor I4 to lever I 6, movement of this pointof attachment will result in a movement of the point of attachment ofservomotor I3 in the same direction, and a corresponding movement ofcamshaft I2 is produced. Since camshaft I2 moves in accordance with themovementsv of the control member of the servomotor, as explained below,it follows that reversing the movement of the control member will resultin reverse movement of camshaft I2. I1 is a manually controlled lever,fulcrumed adjacent its lower end at a fixed axis, and movable in thedirection of the arrow, or counterclockwise, to open the valve 6 to thedesired extent to provide for the supply of air from reservoir "I at acontrolled rate. For any position of the hand lever I1 the valve 6 isset at some predetermined position determining the engine performance bydetermining the mean pressure of the air admitted to the combustionchamber 4 at any speed. The centrifugal regulator I4 controls the engineperformance automatically by automatically changing the torque tomaintain any selected speed. Thus a considerable variation in the enginetorque produced by the work cylinder construction is provided for,qualifying the work cylinder for uses in many i places in place of thesteam engine with its euslisis tomary boiler. The engine operation ofthe present invention, however, is far superior in many respects to theordinary engine and boiler construction as it gives a very widevariation of engine torque with a large temperature dierential betweenthe gas supplied to the expansion chamber and that which exhauststoatmosphere.

In accordance with the construction of Fig. 1 of the drawings theproducts of combustion produced in the combustion chamber 4 are of. veryhigh temperature and of high pressure. The air supplied from thereservoir 1 is also of high pressure, in excess of the pressure producedin the combustion chamber when thefuel is burned at that point. The airsupply from the reservoir chamber 1 is also quite warm as it hasbeenheated up by reason of its compression in the lair compressor 2. and itsheat is maintained by `matically in Fig. 1 and as more fully illustratedin Fig. '7. As the warm air supplied from the compressor 'I flows alongthe hot walls of the combustion chamber 4 the air is further heated tosuch a point that at the particular pressure at which it is supplied itwill cause the ignitionV of the fuel supplied from the fuel pump II tothe combustion chamber. The combustion of the fuel in this air serves tomaintain the Walls of the chamber 4 heated but as previously mentionedan excessively high temperature of these walls is prevented by the flowof air around them.l

As already mentioned, the air compressor 2 is operated without anymechanical driving interconnections with the work cylinder 3 so thatwhen any additional torque is required of the work cylinder 3, when thelatter tends to slow down in its operation, the pressure of the gassupplied to the reservoir 1 can be maintained automatically by theregulator 8, and by -moving the lever I1 to increase the opening of thevalve 6, or by automatic operation of the centrifugal governor 'I4 thecam shaft I2 can be so regulated as to produce av wider opening, and

consequently less throttling in the flow of combustion gases from thecombustion chamber 4 to the expansion chamber' 3. As shown particularlyin Figs. 4a, 4b, 4c and 4d, where a detailed showing is given of themeans' for regulating the produces a change in the lift of valve 5, dueto the configuration of the cams, as shown particularly in the sectionalviews 4b, 4e and- 4d. Thus as vthe shifting of shaft I2 brings a higherpart of the cam under the operating mechanism of valve 5, the lift ofthe valve is increased. The

mean effective pressure of the work chamber.

is therefore controllable.

It will now be apparent that the combustion products generator orchamber 4 is supplied with compressed air and with fuel oil, thecompressed air stream being heated to such a point by passing in contactwith the hot walls of that chamber as to be at the ignition temperaturewhen it reaches the atomized fuel stream. The burning takes place in thechamber 4,the hot products of combustion being then immediately suppliedto the expansion chamber, before the heat contained in the gases isdissipated by radiation andlost. The valve 5 is opened when the piston 3is at or near its top dead center position and the hot products of.combustion and burning gases are supplied to the expansion chamberduring the time of fuel supply to the chamber 4. Moreover the degree ofopening of the valve 5 can be controlled so as to open wider, if moretorque is desired, or'vice versa and when the` torque requirement isincreased theie is also a greater amount of fuel supplied to thecombustion chamber 4, and there is a greater ow of air from thereservoir 1. This creates a greater drain on the air reservoirjbut asthere is a separate source of power for operating the air compressor thelatter can supply an increased amount of air at a time of increasedtorque, and can maintain operation under the increased torquerequirements as long as desired. The torque output may thus be verywidely varied.

Fig. 2 shows a slightly modified form of construction, corresponding inmany respects to the construction shown in Fig. 1. In Fig. 2, the Dieselengine la operates the separate air compressor 2a which supplies air tothe work or expansion cylinder 3a, the air being mixed with the fuel inthe combustion chamber 4a and the hot products of combustion from thecombustion chamber 4a being supplied through the valve 5a to theexpansion cylinder 3a as in the form of construction first described. Amanually controlled valve such as the valve 6 of Fig. l is not employed,the air reservoir chamber 1a being connected directly to the combustionchamber 4a. The pressure of the air in the reservoir chamber 1a can bevaried, however, to provide for different torque requirements of theengine. As herein shown the pressure regulator 8a comprises a pressureresponsive element connected4 to a control lever which is connected inturn to the fuel control part 9a which controls the fuel pump Illa ofthe driving Diesel engine Ia. As illustrated, the pressure responseelement of pressure regulator 8a is connected by rod 225 to lever 226,which is in turn connected by rod 221 to three-armed lever 228. Lever228 is connected to the control part 9a of fuel-pump Illa, and to valve20a.' The pressure of the air Within the reservoir chamber 1a balancesthe pressure re.- sponsive element against a spring I9a, the latterbeing adjustably controlled by means of a ball-crank lever 229 or thelike connected to an operating lever I1a which isv manually adjustabletn cause any predetermined desired air pressure in the chamber 1a.Operating lever I1a can be moved counterclockwise. Such movementproduces an endwise movement of cam rok shaft |2a, by the operation oflever Ita, lever I 8a, and associated connections, the upper end oflever |8a engaging collar 220a on cam shaft |2a. Endwise movement of camshaft |2a increases the lift of valve 5a, and also serves to increasethe output of fuel pump ila. Control part Sa of the fuel pump isconnected to one end of lever 230, the other end of the lever beingconnected to cam shaft |2a. Movement of lever Ila also serves tocompress spring |9a, through the medium of bell crank 229 and associatedlinkage. This produces movement of the pressure responsive element ofregulator 8a, ii. the tension of spring |9a is increased to a point inexcess of the pressure of the air in reservoir `|a t Such movement inturn increases the output i of air compressor 2a through the lmechanismpreviously described. Thus regulator part 9a moves to increase theoutput of fuel pump lila, and lever 20|a is withdrawn to allow valve 20ato function. Pressure in chamber 'la thus increases until the tension ofspring Isa in its new position is balanced.

As the hand lever Ila is adjusted to determine the pressure to bemaintained in the reservoir la, it also controls the setting of the camshaft |2a which' is operated through lever Isa connected to lever IGawhich is fulcrumed at |5a on a manually adjustable fulcrum which can bemoved down to the lower end of the lever |6a in order to provide forreverse operation of the engine. As will be noted, the cam shaft |2aalso drives the pump plunger of fuel pump I la which supplies fuel tothe combustion chamber 4a whereas in the form of construction firstdescribed the fuel pump is operated from a shaft of the compressordriving Diesel engine ia. The

operation of the fuel pump lia is controlled in accordance with thesetting of the cam shaft |2a and in accordance with the setting of thespring |9a so that the quantity of fuel, supplied continuously orperiodically` at predetermined times in the sequence oi' operations ofthe work cylinder, is changed in accordance with the requirements, forthe controlof. engine torque.

If the operating lever Ila is moved as indicated by the arrow, thestroke of the intake valve v5a is increased, increasing the flow to thework/chamber and providing for increased torque, and at the same timethe regulating member for the fuel pumps Ila and lia is changed so as toincrease the fuel quantity delivered to the combustion chamber la and toengine la. This occurs while the control regulator 20a of the aircompressor is changed so as to provide for an increased pressure out-putto lthe air reservoir chamber 1a.

In the construction shown in Fig. 3 there is a further modified form ofthe invention. Here the Diesel engine ib drives the air compressor 2bwhich is independent of any mechanical driving connection or timedoperation with the work or expansion cylinder Ib. The combustion chamber4b is periodically supplied with fuel from a fuel pump lib driven fromcam shaft |2b. The amount of fuel supplied at each operation of the pumpis controlled by a control part Ib which is adjustable in accordancewith the position of the hand lever Ilb which also operates the endwiseadjustable cam shaft I2b for the control d the operation of the inletvalve 5b. As shown, control part I'b is in the form of a rack which, atits lateral movement, turns the pump piston to regulate the fuelquantity. as described in connection with Pig. 1. Control part Sb isadjusted upon endwise movement of the cam shaft through theintermediation of lever 2301). Fig. 13 shows one arrangement by which aportion of the cam shaft which carries the cam controlling the valve 5bmay be given endwise movement under the control of the lever |1b, whilerotatably connected to its driv ing gear. This axially movable portion|2b' is keyed to the spindle portion |2b which rotates on suitablebearings to rotate the movable portion. The movable portion is movedaxially by an operating lever engaging the collar 220b. The air supplyto the air reservoir 1b is automatically maintained at somepredetermined pressure by means of the pressure regulator 8b whichautomatically operates against the tension of a spring I9b balancingagainst the pressure of the air in the reservoir chamber. This pressureregulator controls the fuel pump control part 9b automatically, whichcontrols the operation of the fuel pump |b and which also controls theoperation of the air inlet valve 20h of the air compressor. Air from theair reservoir 'ib is supplied through an automatically controlled valve2| which provides for a controlled throttling of the air flow from thereservoir chamber Ib to the auxiliary reservoir chamber 22 in accordancewith the setting of lever ilb. The pressure valve 2| is automaticallycontrolled by a spring 23 one end of which is adjustably positioned by'means of a manual lever Ilb. As shown, valve 2| comprises valve head-23| movable toward and away from valve seat 232. Head 23| is connectedby stem 233 to pressure responsive element 234, so that compressed airfrom reservoir 1b tends to move the valve to the right. Adjustablespring 23 urges element 23| to the left against the action of the air.Increasing the tension on spring 23 thus varies the amount of airsupplied to auxiliary reservoir 22. 'I'he latter is also connected tothe endwise adjustable cam shaft |2b which controls the lift of inletvalve b. Lever Ilb is also mechanically connected to the control part 9bof the fuel pump lib.

In this form of construction the pressure of the air supplied to thecombustion chamber 4b can be manually varied by adjustment of thesetting of lever I'lb although the pressure of the air in the reservoirchamber is maintained substantially uniform, the pressure reducing valve2| provided ahead of the auxiliary small compressed air container 22providing for such pressure control. These parts provide for taking upthe volumetric increase of the gases due to combustion in space 4b byequalizing the pressure between chamber 22 and space 4b, or by providingan automatic check against flow from chamber 22 to reservoir 1b. Thepressure in the expansion chamber may be increased by shifting the camshaft |2b to cause a larger opening o f the intake valve 5b, and whilethis occurs the regulating member sb of the fuel pump lib increases thefuel supplied directly to the combustion chamber lb.

In this construction the auxiliary container 22 and its supply anddelivery pipes, like the container or reservoir 1b are provided with aheat insulating covering as a protection against heat losses, it beingunderstood that such heat insulation is provided inthe various otherembodiments of the invention.

In the form of construction shown in Fig. 4 the power plant comprisesthe air compressor 2c driven by the engine Ic, the parts le, IIc, 2te,lc

and |c corresponding substantially to the parts of corresponding numbersdiscussed with reference to Figs. 1, 2 and 3. The air reservoir chamber1c, however, is connected directly to the combustion chamber 4c whichsupplies hot combustion gases to the expansion chamber 3c under thecontrol of the mean pressure regulating valve 5c operated by means ofthe movable cam shaft |2c. The latter is positioned by a control leverllc which operates the lever |6c from the lever IBc. Fig. 4a representsthis servomot-or in a larger scale; the method of Working of such aservomotor is generally known. The inner slide valve |3| is actuated bycontrol lever llc. The inlet ports 231 and 238 to the cylinder of theservornotor are controlled by the two inner collars |32, |33 of thedistribution slide valve |3I, whereas the two outside collars |34, |35control the outlet'ports 239 and 24|) from the cylinder. In the positionshown fluid under pressure enters port 238 and acts upon piston 24| tomove it to the left. `At the same time the space to the 'left of piston24| is open to atmosphere through port 239 and holes 242 in sleeve valve|31. For reverse operation, pressure is applied through port 231 to theleft side of piston 24|, and the space to the right of the piston is incommunication-with atmosphere through port 240 and hole 243 in sleevevalve |31. Return sleeve valve |31 is coupled to the piston rod |36 ofthe servomotor by coupling means 236; this sleeve valve again closes theinlet and outlet channels after each displacement of distribution Valve13|., Therefore, each position of the distribution valve |3| correspondsto an exactly xedposition of the servomotor piston and the valve,Ycamshaft |2e. The construction is such thatfshifting of the shaft |2edoes not alter the driving of the fuel pump plunger. The constructionof. shaft `|2e preferably comprises an axially movable portion keyed ona rotatable spindle portion similar to the shaft |2b previouslydescribed. Consequently, the stroke of the inlet valve can be minutelyadjusted or modified without force by control lever |1c. As in the othermodifications, the fulcrum 15o may be moved to the lower end of the4lever |6c to provide for reverse operation of the engine so that thelever |1c may be moved in the same direction to increase the enginetorque regardless of which directionv the engine is operating. In thisform of construction there is an approximately uniformhigh pressure inthe air supply line connected to the combustion chamber 4c.

In the forms of construction illustrated in Figs. 1 to 4 inclusive, theexpansion chamber or work cylinder 3, 3a., 3b, or 3c may. be a singlecylinder or may be a multiplenumber of cylinders, and the combustionchamber 4, 4a, 4b or 4c may also be a single combustion chamber or maybe several combustion chambers, as desired. Fig. 6 shows a modificationof the invention, corresponding substantially to the constructionspreviously described, but incorporating a construction adapted for `aplurality of work cylinders.

AIn. the construction shown in Fig. 6, there are four fuel injectionnozzles l29e corresponding to four combustion chambers 4, 4a, 4b or 4c,constructed in accordance with the construction set forth in Figs. 1 to4 inclusive. 'I'he fuel is supplied to the four fuel nozzles 29e bymeans of four fuel pumps lle, the amount of fuel supplied being governedby a controlled part 9'e that can be moved in one direction to increasethe amount of fuel and moved in the other direction to decrease theamount of fuel supply regardless of which direction the engine isoperating. As herein shown the endwise adjustable control shaft |2e ispositioned by means of a regulator I3e corresponding tor the regulator|3c illustrated in Fig. 4 for example. duration of the injection periodor the amount of fuel injected, for any setting of the cam shaft |2e, byturning the pump plunger simultaneously by means of the rack teeth onthe control part 9'e. The camshaft |2e is provided with intake valveactuating cams 26e for forward operation of the engine and 26'e forreverse running and is provided with exhaust valve actuating cams 30 and30' for forward and reverse running. The rollers provided at the lowerends of the valve lifting rods cooperate with the in'clined surfaces ofthe valve actuating cams 26e so that the intake valve will be open to agreater extent when operating adjacent end portions of the cam 26e,andto a lesser or to a zero extent when operating close to the center orbetweenthe cams 25eV and 26'e. The valve stroke of the exhaust valvepreferably remains constant when the stroke of the inlet valve ischanged.

In this form of construction endwise adjust--l ment of the cam shaft 12ais transmitted to the regulating element Be through three double levers32, 33 and 34. Movement of the cam shaft |2e toward the right operatesthroughlever 32 merely to compress spring 35, since the spring plate 31'is slidable on rod 245, formed as an extension of rack 9'e, levers 33and 34 serving to positively move thel fuel pump control part 9e towardsthe right, since the flanged collar 38 is fast on rod 245. 'I'he part9'e is moved to the right, however, even when the cam shaft |2e is movedto the left, because when that takes place the lever 32 positively movesthe part 9'e by engagement with anged collar 31 which is fast on the rod245. Levers 33 and 34 operate merely to compress .the spring 36 throughspring plate 38 slidable on rod 245, and are ineffective. Thusregardless of. the position of the adjustment of the cam shaft |2e,either for forward or reverse running of vthe engine, movement of theshaft in one direction such as will move the cam roller from a pointcorresponding to minimum opening of the inlet valve 5, 5a, 5b or 5c willproduce a Vmovement of the fuel pump control part S'c such as to causean increase in the fuel quantity supply.

Fig. 5 represents the timing of the fuel injection and of the openingand closing of the valve 5, 5a, 5b'or 5c, for the constructionillustrated in Fig. 6. Here the time during which the valve 5, 5a, 5b or5c of any cylinder is closed, as represented by angle fi, is quite longas compared to the time the gas is owing past the valve inasmuch as thevalve for each cylinder controls the ow of hot gases generated from oneinjector means. In this figure the angle a represents the time andduration of the opening of an inlet This controls thevalve and thesmaller angle represents the duration of fuel injection at a fuelnozzle.

Fig. 7 shows a preferred form of construction of the combustion chamberand of the air and fuel conduits and passages provided ahead of theexpansion chamber of any of the modifications of the inventiondescribed. In the description of the construction of Fig. 7 the samereference numerals have been employed to designate corresponding partsof the other modifications, although a diierent suiiix letter is used.The work cylinder or expansion chamber is represented by the referencenumeral 3f, 53 designating the Work piston. The hot products ofcombustion are supplied to the work cylinder through the valve 5f, whichis operated by the fork 46 of a cam control member as will be laterdescribed. The fuel which is supplied as an oil stream to the fuelinjection nozzle 29j' is injected into the combustion space 4f. Thecompressed air from the air compressor enters through the pipe line 39at approximately the temperature of the air in the last stage of themultiple stage compressor.

i Where the burning in the combustion chamber 4f occurs intermittentlyor at different predetermined times in the sequence of each cycle ofoperation of the work cylinders, and where the volumetric increaseoccurring during combustion is utilized to increase the pressure of thecombustion gases ahead of the intake valve 5f, then the warm compressedair passes first through an automatic check valve winch prevents thereturn of air back through the pipe line 39. 'I'he air then enters theair passage 4I which extends aroundthe passage provided for `the hotproducts of combustion. to which the reference numeral 42 has beenapplied. In flowing along the passage 4i the walls of the passage l2 arecooled, and the compressed air is heated up very materially so as to`beat least as hot as the ignition temperature of the fuel in the chamber4f. The walls of the passage 42 are hot enough, however, to provideautomatically for the ignition of the fuel at the prevailing temperatureas the fuel enters the combustion chamber 4f. After being heated, theheated compressed air enters the top of the combustion chamber 4fradially and from different sides. fiowing generally towards the fuelinjection nozzle 29j' from which the fuel isdirected in radially outwardstreams and at high speed. The outwardly directed fuel therefore meetsthe inwardly directed air streams at relatively high velocity so as toproduce a thorough atomization of the fuel and an intimatecontact of thefuel particles with the oxygen molecules that are unusually closetogether by reason of the high pressure prevailing. 'Ihis gives such athorough mixing as to produce complete combustion of the fuel. Themaximum combustion temperature of the fuel is extremely high due to thefact that ,the temperature of the combustion air supplied to thecombustion chamber 4f is quite high.

To provide for ready starting of the power plant, when cold, ignition ofthe fuel in the combustion chamber 4f is obtained by means of a glowplug 44, arranged in a side of the combustion chamber and adapted to beelectrically energized at low voltage to produce a glowing temperatureoi the heating element which, if desired, may be arranged in a smallantichamber of the combustion chamber near the fuel entrance. as shown.

The outer wall of the air passage 4| is surrounded by a heat protectivechamber 4l which,

as illustrated in Fig. "l, is in communication with the water coolingjacket of the cylinder 3f. The chamber may be filled with cooling water,or may contain dead air or other heat insulating material. The heattransmitted through the wall enclosing the air passage 4i is thus quiterestricted, if dead air or other heat insulating material is employed,so that little heat is lost. The heat transmitted to the compressed airitself while passing through the passage 4I is utilized in the workprocess in the form of energy.

The combustion chamber 4f and the various air passages are arranged, asshown, in a head or housing constituting the head of the cylinder 3f andproviding a, short passage of small volume between the valve 5f and theexpansion chamber 3f so that the volume of gas required to fill thispassage is quite restricted. This housing is provided with a detachableportion that can be removed for inspection of the incandescent startingplug 44 and for inspection of the readily removable combustion chamberwalls including the combustion gas' passage 42. The housing of thecombustion chamber is also provided with a recess in which is removablythreaded the guide portion of the inlet valve 5f. The latter isreciprocated in the guide portion by means of the fork 46 of a camoperated member, which controls the opening of the valve 5f against thetension of a compression spring 46. The upwardly extending portion ofthe valve 5f is stationary, held so by the hollow stems or pipes 41' and41", and a suitable supporting bracket, the valve being supplied with`cooling liquid such as cooling water supplied under pressure for entrythrough a hollowstem 41 leading through the stationary portion 41, thecooling water being taken oif through an outlet pipe 41" connected to aside of this valve portion 41. To lubricate the intake valve 5f and thestationary valve portion 41 an oil conduit 48 is provided, connected toan oil supply reservoir, not shown, which supplies oil under suitablepressure.

Fig. l0 illustrates the pressure volume curve of the work or expansionchamber of an engine con structed in accordance with the modificationsshown in Figs. 2 and 3, and in which the engine operates at a. variableintake pressure but with a uniform comparatively short filling period.During forward operation of the engine at high speed, the pressure ofthe hot combustion gases exerted on the piston changes approximately inaccordance with the line 55. When the load increases the speed tends todecrease and this automatically increases the intake pressure of thecompressed air if necessary up to about 100 kilograms per squarecentimeter to provide a pressure volume curve in accordance with thecurve represented by the line 56, in which the ba'se line representsnormal atmospheric pressure.

As compared with the known engine constructions in which wide variationsin torque are possible, such for example as a steam engine, the powerplant of the present invention has the advantage in that it operateswith a comparatively short iilling period, represented in Fig. 10 by tl.e distance between the vertical solid line at the lefthand of thediagram curve and the vertical dash line. The present constructiontherefore provides for correspondingly low exhaust pressures andextremely low exhaust gas temperatures, thus minimizing the exhaust gasloss even when the torque requirementsare considerably high.

Fig. 11 represents the left-hand end of the pressure volume diagram ofthe power plant represented in Figs. 1 and 4. In these modifications theengine operates with substantially constant maximum intake pressure, andthe angular duration of time, angle a, during which the intake valve 5,5a, 5b or 5c is open is substantially constant. The crank angle almeasuring from the outer piston dead center position to the time ofclosing of the intake valve 5, 5a, 5b or 5c is indicated in this diagramFig. 11. this angle being the difference between angle a and thepre-intake angle or angle ahead of dead center. The engine operates witha varying iilling or charge of the work cylinder at diierent speeds,because here there is an intentional throttling of the combustion gasesflowing to the work chamber 3, 3a, 3b or 3c in order to automaticallyreduce the time of filling at the higher operating speeds. The energytransmission through the intake valve 5, 5a, 5b or 5c is automaticallythrottled to change the mean pressure of the combustion gases suppliedto the work chamber at any speed, and this gives an automatic control ofthe torque at different speeds. This especially adapts the constructionto a power plant suitable for driving an automatic vehicle or the likewhere the power requirements diier widely at different times and wherethe torque requirements are quite large at lower speeds.

As shown in the diagram of Fig. 11 the pressure curve 51 corresponds tomaximum speed conditions, the pressure curve l58 corresponding to alower engine speed. This'diagram furthermore shows other curves in dashlines. such as the line 59, indicating the lspeed of iiow of theproducts of combustion through the intake valve 5, 5a, 5b or 5c at themaximum engine speed, curve 55 indieating the speed of gas flow at a lowengine speed corresponding to the increased engine torque of full engineperformance. The additional dash lines shown between curves 59 and 50represent `deviation from the solid line of the pressure volume diagramon which the calculations are based. The intersecting points oi'. theverticalV line 62 designating the time of valve closure with thepressure lines 51 and 58, as represented by points 51a and 58a, indicatethe pressure of the Y combustion gases at the time oi the closing of theintake valve 5, 5a, 5b or 5c. The degree of the automatic throttlingaction changes up to the time the valve is closed. This throttlingaction provides an automatic change in the engine torque in accordancewith the speed of operation,

as the full pressure of the combustion gases in chamber I, la, 4b or 4cis applied to the expansion chamber for only a part of the time thevalve 5,. 5a. 5b or 5c is open. The valve closing line 52 of the diagramrepresents a charge time of about 14% of a stroke of the work piston.The `theoretical pressure curve 51 corresponds to high speed operationin which there is a lling of about 1.5% of thetotal piston stroke duringwhich the maximum pressure is supplied. Curve 58 corresponds to atheoretical pressure volume diagram in which there is a charging atmaximum pre's- -sure only during about 10% of the piston stroke.

As can be noted the eflect of the automatic throttling due to thelimited opening travel of valve 5, 5a, 5b or llic is much greater, inproportion, during high speed operation.

As will now be apparent, the engine operates with unusually smallcharging time during which fuel and air are supplied to the workchamber,and'with .low iinal pressures of the exhaust and with correspondinglylow exhaust gas temperatures and small gas losses. As will also beapparent the engine of the prsent invention operates with widely varyingtorque and with an unusually large `differential between the hightemperature of the charging gas, and the temperature of the exhaust,resulting in unusual economy.

While the method herein described and the forms of apparatus forcarrying this method into effect, constitute preferred embodiments ofthe invention, it is to be understood that the invention is not limitedto this precise method and forms of apparatus. and that changes may bemade in either without departing from the scope of the invention whichis defined in the appended claims.

What is claimed is:

' 1. A combustion engine of the character described comprising a gasexpansion chamber having a movable work member, a combustion chamber inwhich combustion gases are produced sufcient` for the power operation ofsaid movable work member, said combustion chamber being ilxed in closeproximity to the expansion chamber, supply means of short lengthextending vdirectly from the combustion chamber to the expansion chamberand having a valve operable to vary the ilow of combustion gasessupplied to the expansion chamber, an air compressor, an auxiliaryengine for operating said compressor, said auxiliary engine beingindependent of any energy drain on the combustion chamber, means forcontrolling the output of said auxiliary en' gine, a passage in heatconducting communication with and extending around said combustionchamber and having a discharge opening communicating with the combustionchamber, means for supplying compressed air from said compressor to saidpassagey at a point remote from said discharge opening to heat the airand cool the combustion chamber, means for periodically injecting fuelto the combustion chamber in the normal operation of the combustionengine, means for operating said valve in timed relation to themovements of said movable work member to open the valve before the timeof fuel injection to the combustion chamber, and means for controllingthe weight of combustion gases supplied per cycle of operation ofthework member.

2. lli` combustion engine of the character described comprising a `gasexpansion chamber having a movable work member, a combustion chamber inwhich combustion gases are produced sufiicient for the power operationof said movable work member, said combustion chamber being xed in closeproximity to the expansion chamber, supply means of short lengthextending directly from the combustion chamber to the expansion chamberand having a valve operable to vary the flow of combustion gasessupplied to the expansion chamber, an air compressor, an auxiliaryengine for operating said compressor, said auxiliary engine-beingindependent of any energy drain on the combustion chamber, means forcontrolling the output of said auxiliary engine, a passage inheatconducting communication with and extending around said combustionchamber and having a discharge opening comfor supplying compressed airfrom said compressor to said passage at a point remote from saiddischarge opening to heat the air and cool the combustion chamber, meansfor supplying fuel to the combustion chamber in timed relation to themovements of said movable work member and during the normal operation ofthe combustion engine, means for opening and closing said valve in timedrelation to the movements of said movable work member said.meansoperating to open the valve before the -time of fuel supply to thecombustion chamber, and means for controlling said valve to vary theamount of combustion gases supplied per cycle of operation of themovable work member.

3. A combustion engine of the character described comprising a gasexpansion chamber having a movable work member, a combustion chamber inwhich combustion gases are produced sumcient for the power operation ofsaid movable work member, said combustion chamber being fixed in closeproximity to the expansion chamber, supply means oishort lengthextending directly from the combustion chamber to the expansion chamberand having a valve operable to vary the ilow of combustion gasessupplied to the expansion chamber, an air compressor, an auxiliaryengine for operating said compressor, said I auxiliary engine beingindependent of any energy drain on the combustion chamber, meansmunicating with the combustion chamber, means" opening and closing ofsaid valve in timed relation to the movements of said movable workmember, control means for controlling said valve operating means to varythe amount of combustion gases supplied per cycle of operation of saidmovable work member and to vary the direction of rotation of the engine,a fuel regulating mem'- ber for controlling the amount of fuel suppliedto the combustion chamber, and a connection between said'fuel regulatingmember and said control means for movement of the fuel regulating memberin the same direction to increase the amount of fuel supplied to thecombustion chamber in both forward and reverse operation of the engineas the amount of combustion gases supplied per cycle of operation of themovable work member increases.

HERMANN RIESEIER. 30

